Any player can fall into a slump at any given time. No matter how good they are, at some point, it will happen.
Self evaluation is key. Mental toughness is key. Perseverance is key. You need to be able to think about what it, physically and mentally, was like when things were going good. You need to be able to stay positive and visualize those great days. And you need to keep pushing. Trust the process as you can learn more from a slump than a 4 for 4 day or 7 shutout innings.
Slumps expose your weaknesses. Yes, you have weaknesses. The better you are at the things stated above, the shorter and shorter the slumps will last.
Remember this too. When a slump hits, it doesn’t mean you have to recreate your swing or delivery. Find some video. Find some pictures. Get back to what it was like when things were right. Easier said than done sometimes, but don’t get too technical. More often than not, you need a mental adjustment. You need to believe. You need more positive thoughts. You need a plan, even if that plan is to have a clear mind. The mind is a powerful thing. It can make you or it can break you.
Trust the process and learn everyday. Be Humble as those with a humble mentality seem to handle this type of adversity much better than those who think they have it all figured out.